In the field of electric vehicles, a technique called regenerative charging that charges a battery by recovering regenerative power generated when braking a motor (load) is known. Use of this technique reduces battery consumption. In this technique, when driving the motor, a power supply path on a discharge circuit side is selected by a switching means, and power is supplied from the battery to the load. On the other hand, when regenerative power is generated by the motor, the power supply path is switched from the discharge circuit side to a charge circuit side by the switching means, and the battery is charged with the regenerative power. In this manner, the power supply path between the battery and the motor is switched by the switching means.
In a typical electric two-wheel vehicle and electric four-wheel vehicle, a throttle is operated for acceleration and a brake is operated for deceleration, and the switching is relatively slow and smooth. Therefore, when applying the known technique of regenerative charging to those electric vehicles, the power supply path between the battery and the motor is actively switched, triggered by the operation of the throttle or the brake, and the battery charging with the regenerative power is performed without waste.
On the other hand, an inverted two-wheel vehicle with two coaxially-mounted wheels that is controlled by the inverted pendulum theory needs to always maintain balance using two wheels. Thus, when applying the known technique of regenerative charging to the inverted two-wheel vehicle, drive mode in which the battery drives the motor and regeneration mode in which regenerative power is generated by the motor are switched in very short periods. Therefore, with the known technique of regenerative charging, the power supply path cannot be switched in response to high-speed charging and discharging of the inverted two-wheel vehicle. Accordingly, the known inverted two-wheel vehicle has not been able to charge a battery by efficiently recovering regenerative power.
A control device that charges a battery with regenerative power and does not include a switching means for switching a power supply path between the battery and a motor is disclosed in Patent Literature 1 (cf. FIG. 4 of Patent Literature 1). Because the control device does not include the switching means for switching the power supply path between the battery and the motor, the above-described problem does not occur.